What effect does the sympathetic nervous system have on respiration?

• A. It constricts airways to reduce airflow
• B. It dilates airways to increase airflow
• C. It has no effect on respiration
• D. It increases mucus production

Answer: (B)

The sympathetic nervous system plays a crucial role in the body's response to stress and physical activity, commonly known as the "fight or flight" response. When activated, it causes dilation of the airways, which is accomplished through the relaxation of the smooth muscles surrounding the bronchial passages. This dilation increases airflow into the lungs, allowing for greater oxygen intake and improved gas exchange. This mechanism is particularly important during times of physical exertion or stress when the body requires more oxygen.

Additionally, the increased airflow helps to enhance physical performance and quicken the body's response to various stimuli. In contrast, the other options either suggest a reduction in airflow, an absence of effect on respiration, or an increase in mucus production, which do not align with the sympathetic nervous system's primary function of promoting airflow during heightened states of activity. This physiological response emphasizes the importance of the sympathetic nervous system in optimizing respiratory function in demanding situations.